Quantum Computers v.s. Bitcoin
How is cryptography vulnerable under quantum computing power
Quantum computing has long been Sci-fi movie topics, which a super computer poses significant threats in the tech world by outraging cyber firewalls and taking over nuclear weapons within seconds. As these futuristic machines are closer to reality, one question comes up.
Will quantum computers break Bitcoin?
In this post, we’ll dive into the course why quantum computing poses a potential threat to Bitcoin’s security, how serious the danger truly is, and what precautions can crypto developer can do to mitigate it.
The Quantum Leap: Qubits matter
Quantum computers leverage quantum bits (qubits) to perform calculation, which can simultaneously proceed an extensive amount of possibilities at once, while the traditional laptops are only capable of dealing single calculation at a time.
This speedy computing innovation isn’t just a marginal upgrade. It unlocks the potential to solve complex mathematics problems that are practically impossible, including the security mechanisms underpin the overall cryptography.
There are two aspects of Bitcoin network that matter the most.
1. ECDSA (Elliptic Curve Digital Signature Algorithm)
In plain texts: If quantum machines become fast enough, your private keys can be trivially derived from your public keys, making your wallet widely open to public.
The Bitcoin network relies on asymmetric cryptography or ECDSA: a private-public key pair is generated in such a manner that the two keys have a mathematical relationship. The “asymmetric” indicates the important concept that public key can be easily derived from the private key but mathematically impossible to reverse. However, a famous algorithm published in 1994 by Peter Shor, known as Shore’s Algorithm, demonstrated that the quantum computers can shatter this “ invincible” cryptography.
Currently, it takes around 10 minutes for transactions being settled in Bitcoin network. As long as the quantum computers can’t solve the cryptography within the slots, then the threat attack is nonsense.
According to scientific estimation, the modern technique of quantum takes 8 hours to break the private key, which is far from an instant threat to cryptocurrency. However, the field is still in its infancy and expected to grow exponentially. The fud could come to reality in the coming years.
2. SHA-256 Algorithm
In plain texts: Quantum computers give miners overwhelming advantages to secure block and new coin rewards (BTC)
Bitcoin utilizes the Proof-of-Work (PoW) consensus, which “miners” compete computational races to validate transaction batches. Whoever wins the competition is entitled to build the blocks and get awarded with minted coins.
This race requires continually hashing data using the SHA-256. Quantum computers dramatically reduce the time needed to clean the hash with another powerful technique called Grover's Algorithm. Grover is designed to speed up brute-force searches through unstructured data. Miners who possess these cutting-edge quantum resources would gain asymmetric benefits to constantly win the block, or BTC over other competitors.
While the “miner monopoly” raises centralization concerns, the ability to breach private keys poses critical threats to the entire crypto industry.
Quantum computing threatens to turn encrypted assets into “naked ”data and melt down the ownership in the digital world. In this case the security of the blockchain will be fundamentally broken.
Certain leaders such as Vitalik (Ethereum founder) has dedicated to steer Etherum toward post-quantum cryptography solutions. Bitcoin community, however, has not yet witnessed a clear direction on how to fundamentally mitigate the upcoming threat.
In short: Quantum attacks are not imminent today, but they represent critical threats that the entire crypto world will face. Then the question relies on, when the crypto developers are well-prepared for its impact.